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Old 02-18-2007, 01:24 AM   #1
ken cz
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Talking How do I estimate flight duration?

What is the formula for estimating flight duration?
For instance, I have:

3S-4200 Lipo 15c
12x8E Prop
Motor draws 8-9 amps at 1/2 throttle/95 watts
Motor draws 30-31 amps at fulll throttle/320 watts

I just do not know enough about EP to understand the math.

Thanks! Ken
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Old 02-18-2007, 06:09 AM   #2
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Hi Ken -

The basic formula is:

(battery capacity/average current consumption) x 60 = flight time in minutes

For your system, we know battery capacity is 4200 mAh = 4.2Ah.
Let's assume average in-flight current consumption is 20A.

So the calculation is:
4.2/20 x 60 = 12.6 minutes

One can add many disclaimers here. For example, it does not take into account efficiency or where your LVC (low voltage cutoff) is set. But, assuming you fly until the battery pack voltage is down to the lowest safe level, this will give you a very rough estimate of flight time.

- Jeff

AMA 787105
My other hobby: AstronomyBoy.com
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Old 02-18-2007, 11:23 AM   #3
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Thumbs up cool.

Ken and Jeff,

Just letting you know that your Q & A helped some one else who was wondering the same thing.
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